Device for feeding band material



Nov. 8, 1966 s. A. AxLlD ETAL DEVICE FOR FEEDING BAND MATERIAL 5Sheets-Sheet 1 Filed May l0, 1965 A sa s el.

Nov. 8, 1966 s. A. AxLlD ETAL DEVICE FOR FEEDING BAND MATERIAL 5Sheets-Sheet 2 Filed May l0, 1965 Fig.3

Nov. 8, 1966 s. A. AXLID ETAL. 3,283,628

DEVICE FOR FEEDING BAND MATERIAL Filed May 10, 1965 5 Sheets-Sheet 3United States Patent O 3,283,628 DEVICE FOR FEEDNG BAND MATERIAL Sven A.Axiid, JakobSberg, Rudolf F. Greiner, Alvsjo, and Gunnar Winkler,Bromma, Sweden, assiguors to Arenco Aktiebolag, Stoclrholm-Vallinghy,Sweden Fiied May 10, 1965, Ser. No. 454,310

Claims priority, application Sweden, May 14, 1964,

3 Claims. (Cl. 553-74) The present invention is an improvement inadvancing units for various types of strip material, eg. paper webs. Theinvention particularly relates to cutting or punching machines forcutting tjhe strip into sheets of equal size, whereby feeding of thestrip is carried out at a certain speed in relation to the movement of aknife, punch or the like. The size, and accuracy of size, is determinedby the driving speed of the drive arrangement which feeds the striprelatively to the speed of a rotating knife or punch, which drivingspeed is composed, in a differential, of magnitudes from a gear or thelike which, parallel with a variator via the differential, transmits thedriving force from an engine to at least one feeding roller.

The problem of feeding strip material to a definite position and indefinite lengths is recognized in a number `of industrial fields, forexample manufacturers of packeting media, and printing works. The degreeof ease in which the problem can be resolved depends on the propertiesof the strip material, the required accuracy in the fed length and thefeeding speed. The importance of high accuracy in the feeding is obviousin most cases. Such is the case, for example, in multicolour printing,where a paper web passes several printing rollers and its position oneach r-oll must lie within very close limits. High accuracy in feedingis also required when cutting sheets from a paper web that has beenpreviously printed upon, whereby the printed pattern has a definiteposition on the sheet.

Feeding units of a more, or less, complex nature, are known from theearlier techniques. Principally it is possible to feed a strip by meansof a driven roll which presses against the strip and rotates through acertain angle corresponding to the required length or size. Accuracy,however, is poor with the use of such simple means due to the fact thatthe strip bends, and, possibly due to the eccentricity in the mountingof the roller or varying slippage between strip and roll. In order toachieve a better result the feeding movement must therefor be correctedin relation to the movement of the knife, punch, etc. In a knownarrangement, the driving force is transmitted from a motor to the wormgear of a differential, where one of the two driven shafts is connectedto a feeding roll, while the other carries a stepping arrangement,comprising a ratchet wheel attached to the shaft, and a pawl releasedelectrically, said pawl, when in the locking position, prevents theratchet wheel and the shaft from rotating. The arrangement is driven sothat a certain over feeding of the strip material occurs. The positionof the fed strip is continuously recorded by means of a controlarrangement, and when the position due to overfeeding, exceeds a certainmargin, the pawl in the stepping arrangement is released and a portionof the feeding movement supplied from the engine runs out through theratchet wheel which is thereafter re-locked. While the ratchet wheel isrotating, the feeding of the strip is reduced whereby a correction ofthe position of the strip relative to a rotating knife, punch etc. iscarried out. Corrections are not made for each length fed between twocuts, instead a varying number of lengths are fed between eachcorrection depending upon the magnitude of over-feeding and correction.The

ice

arrangement now being described usually gives an taccuracy of from oneto two millimetres in the feeding lengths. The accuracy here is combinedwith the magnitude of the correction and this can not be madearbitrarily small since paper of various types or various batches aremore or less easy to feed due to the varying friction, stretch etc. andthis influences the size of the over-feed.

Large overfeeding requires large correction, and it must always be takeninto account that the length of the sheet when cutting, for example,strips havin-g printed patterns, can vary due to poor accuracy whenprinting, different moisture contents of the paper etc., which is whythe correction must be determined in accordance with the outer limitsdemanded by tihese properties. It is also known to construct feedingunits which .give a very high degree of accuracy with respect to thefeeding lengths such as i0.l to 0.2 mm. This unit is more complicated,and is expensive to produce. A unit which closely approaches the unitdescribed above can be mentioned as a simple example of such units. Iftihe stepping arrangement in this unit is exchanged for a variatordriven by a motor, a feeding movement can also be transmitted to thedif-I ferential in this way. The movement of the feeding rolls iscomposed of two magnitudes, rstly the movement transmitted over the wormdrive of the differential, secondly the movement supplied over thevariator onto the second input shaft of the differential. The r.p.m. onthe output shaft of the variator is adjusted on the variator by a servomotor which in turn can be controlled by an amplifier, the input ofwhich is actuated by a control arrangement which records the position ofthe strip relative to a knife, punch etc. Displacements in the positionof the strip are registered in the amplifier which, when necessary,gives the servo motor a signal for adjusting the number of revolutionsof the variator.

The present invention constitutes an improvement of the feeding unitsknown or used at present, and the irnprovement lies in that the simpleand robust construction of the stepping arrangement is combined with theaccuracy of the servo arrangement. The arrangement according to theinvention has at least one feeding roll for a continuous strip material,for example a paper web, which roll is driven by means of a transmissioncomprising a differential, which is driven from two directions by meansof a gear or the like, and a variator, directly connected with acoupling which during short periods can disengage the drive over thevariator. The advantage with this arrangement when compared with thedescribed feeding unit having stepping arrangements, is that it ispossible to set a suitable over-feed on the variator so that themagnitude of the correction can be held reasonably low and fitting forthe section of the strip which i-s being worked upon at that moment.Should a certain section of the strip be easier to feed, the over-feedis reduced by the adjustments on the variator and the correction can beheld constantly low. In the subject of the invention the correction iscarried out in that said coupling, for a brief period, disengages thedrive over the variator and brakes the shaft of the differentialconnected to the coupling, which means that the feeding of the -strip isreduced for a moment. The arrangement can also be operated so that anunderfeeding is effected, whereby the proportions become analogous withthe case for over-feeding, with the difference that feeding during themoment of correction increases instead of decreases. The aforesaidadvantage of being able to maintain the correction constantly low,naturally implies that the accuracy in the fed lengths is greater withthe subject of the invention than with previously known arrangements,and for good accuracy in the pattern printed on the strip it should bepossible to keep deviations within approximately 0.5 mm. An advantage isalso gained in that the variator and the coupling lie on the same shaftas the differential, since due to this a sequence of machine members issaved, which would otherwise be necessary if the previously knownarrangement were to be completed with only a variator and a drivingarrangement for the same. Another advantage with the subject of theinvention is that no servo motor is inclu-ded in the arrangement whichmeans that it is more reliable in operation than feeding units whichhave been fitted with such motors.

The invention is described below in connection with the attached drawingof which FIG. 1 shows the mechanical construction of the arrangementaccording to the invention seen in a vertical projection, FIG. 2 showsthe same arrangement in a horizontal projection, FIG. 3 shows adiagrammatic arrangement in perspective with the electrical circuitsincluded in the gure, and FIG. 4 an electric control circuit which isused for setting the number of revolutions of the variator.

As can be seen from FIGS. l and 2, the arrangement comprises a number ofmachine members which are mounted on a machine frame 1. The stripmaterial 2 is advanced by a feeding roll 3, the shaft 4 of which ismounted in the frame 1, over a table 5 to a rotating knife 6 mounted ona sector which is seated on a shaft 7 mounted in the frame 1. Below thefeeding roll 3 is situated another roll 8 journalled on a shaft 9, whichis pivotally mounted by means of an arm 11 on another shaft 1Q securedto the frame. Pressure is exerted on this roller by means of a spring12, one end of which is secured to the arm 11 and the other end in theframe, against the strip material 2 and the feeding roll 3, whereby thefriction between said strip and feeding roll increases. rl`he end of thetable 5 facing the shaft of the knife 7 is given an edge piece 13provided with a sharp edge 14 against which the knife 6 operates.

A sprocket wheel 15 is securely attached to the shaft 7, a chain (notshown) transfers a force to said sprocket Wheel 15 from a motor; alsonot shown. The motor thus drives the knife 6 but also the feeding roll 3via a transmission which partly comprises gears 16, 17 and 18 and adifferential 19, and partly gears 20 and 21, bevellcd drive 22 and 23, avariator 24, a combined electro magnetic coupling and brake 25, 26respectively and the differential 19. The two gears 16 and 2! aresecurely attached to the shaft 7 and drive against the gears 17 and 21respectively. The gear Wheel 17 is mounted on the neck of a shaft 27,which is secured to the frame by means of a bolt 28. The gear wheel 18is driven from the gear wheel 17, the gear wheel 18 being in a certaintransmission ratio to the gear wheel 16. It is this ratio whichdetermines the size of the cut sheets. In order to alter the size of thesheet the gear wheels 16 and 17 are changed for other gears whichcorrespond to the transmission ratio required for said new size. Thegear wheel 18 is rotatably mounted on the shaft 4 and is in directconnection with a centre gear wheel 29 `situated in the differential.The gear wheel 21 is securely attached to a shaft 30 which is mounted inthe frame and which transmits the force to the bevel gear drive 22, alsosecurely attached to the shaft 30. The force is subsequently transmittedto the shaft 31 due to the fact that the bevel gear drive 22 drives thebevel gear drive 23 which is securely attached to this shaft. From thispoint the input shaft 33 of the variator 24 is driven via a shaftcoupling 32. This variator 4is of conventional design with frictionsurfaces and adjustable movement transmission members. The transmittedmovement in the variator is transferred from the output shaft 34 of thevariator to the electro magnetic coupling 25, which has an armature 35common to the electro magnetic brake 26. The shaft 36 of the couplingmounted in the frame is coupled when the coupling coil 37 is energized,to the shaft 34 due to the fact that the armature 35 is displacedaxially towards this shaft. When current is supplied to the braking coil38, the shaft 36 is coupled to the frame due to the displacement of thearmature in another direction. The armature rotates together with theshaft 36, and the intermediary piece 39 is securely connected to theframe. The movement, by means of a worm screw 40 which is securelyattached to the shaft 36, is transmitted to the worm wheel 41 of thedifferential, whereafter the movement, via compensating wheel drive 42and 43 journalled on the shaft pins 44 and 45, respectively which aresecurely bolted to the worm wheel 41, is combined with `the movementfrom the gear wheel 16, 17 and 18, since the drives 42 and 43 driveagainst the centre gear Wheel 29. The combined movement is transferredvia a second centre gear wheel 46, securely attached to the shaft 4, tothe feeding roll 3.

The electrical couplings, together with a diagrammatic illustration ofthe mechanical constructions, are shown'in FIG. 3. As was stated above,the corrections are carried out in the arrangement by disengaging thedrive over the variator by means of an electro magnetic coupling andbrake. The electro magnetic coupling is energized when its coil isalive, said coil being supplied with current during the time between twocorrections. The circuit for this current passes from the positive poleover a relay contact 47 through the coupling coil 37 to the negativepole. When a correction is made, the contact spring 48 changes itsposition from the relay contact 47 to contact 49, whereby the current tothe coupling coil 37 is broken and the brake coil 38 receives thecurrent instead. Thereby the shaft 36 is braked during that period thecontact spring abuts the contact 49. The contact spring and the contactsbelong to relay 54B which has two relay coils 51 and 52, both of whichhaving one end connected to the minus pole. The supply of current to thecoil 51 is carried out over a relay contact 53, belonging to anotherrelay 54, and a relay contact 55 on the relay 50. The coil 52 obtainscurrent over a switch S6 which is controlled by a cam disc 57, securelyattached to `the shaft 7. The relay 54 also has two relay coils 58 and59 of which the first mentioned is included in a circuit comprising aswitch 60 which is controlled by a cam disc 61 on the shaft 7, the coil58 and the output of a thyratron amplifier 62. The circuit over coil 59is closed over the relay contacts 55 and 63 on the relays 5) and 54respectively. The input of the amplifier 62 is connected to a photo cell64 placed adjacent to the strip 2 and sensitive to reflecting lightspots 65 on the strip. The lamp 66 illuminates these necks of light,whereby the light is reflected against the photo cell. The signals fromthe photo cell are amplitied in the amplifier, a thyraton being includedin the final stages of the same. The amplified signals prepare theignition of the thyratron which occurs if a positive voltage enters, atthe same time as the signal from the photo cell, the anode of thethyratron from the coil 58 and the switch 60. Ignition of the thyratronmeans that the coil 58 receives current and that the relay 54 isenergized.

The function of the electrical system is as follows. When energized, therelay 50 holds over the coil 51 and the contacts 53 and 55. The selfholding implies that the coupling coil 37 lies connected. When the relay54 is energized the self-holding circuit is broken but relay 50 is heldenergized by the coil 52 which is kept supplied with current as long asthe switch 56 is not influenced. The relay 54V takes self-holding overthe coil 59 and the contacts 63 and 55. When the cam of the cam disc 57inuences the switch 56 the current is broken by the coil 52 and therelay 50 falls, whereby the brake coil 38 is connected and theself-holding for the relay 54 ceases. When the cam of the cam disc haspassed the switch, the current is again closed by coil 52, the relay isenergized and takes self-holding and the coupling coil 37 isre-connected. This sequence occurs when a correction is made.

When this condition for correction is not fulfilled, which occurs whenthere is no synchronization between the signal of the photo cell and thepositive voltage from the switch 60, the relay 54 is not energized sincethe thyraton is then not ignited and no current is closed through thecoil 58. The self-holding circuit for the relay 50 is not broken, whichis why this relay lies closed the whole time and the coupling coil 37connected. Thus the determination of the position of the strip 2 inrelation to the rotating knife 6 is effected by a photo-cell sensing offlecks, marks or the like which are printed or otherwise attached to thestrip 2 at a mutual distance equal to the length of the size. Thus, foreach length of strip advanced the photo cell is infiuenced once andsends a signal to the amplifier 62. The flecks are also used for a firstrough adjustment of the position of the strip relative to the knife. Ascale 67 is marked out on the feeding table 5, against which a fieck onthe strip is positioned at the same time as two indicators 68 and 69marked out on the knife and machine frame respectively lie opposite oneanother. This adjustment is made before a feeding begins, and when theunit is then started the position of the strip coincides relativelyclose to that of the knife so that a correction of the positionaccording to the above can ybe carried out very quickly and withoutunnecessary waste of strip material due to a wrong cutting.

In order to facilitate a quick or rapid adjustment of the variator, thearrangement is lprovided with an electric control circuit having anindicator from which the closeness of the corrections can be read, forexample how many lengths are fed between two corrections. It ispossible, by means of the indicator, to see if the corrections occur,during a machine operation, at the right speed in sequence, that is tosay not too close but neit-her to widely spaced. The electrical controlcircuit can be designed the same as that described in the Swedishspecifi-cation 171,687. According to this specification the controlcircuit comprises a relay arrangement (see FIG. 4) having a plurality ofpart circuits with 1an input circuit, comprising a condenser 69 forstoring an electric .pulse and an output circuit, comprising a relaymember 70, a switch 71, the contacts of which are influenced by arotating cam disc 72 and connect the condenser and relay member inseries so that the pulse stored in the condensator energizes the relaymember, thereby a corresponding pulse is transmitted to and stored bythe -condenser 73 in a subsequent part circuit. The cam disc 72similarly to another car;` disc 74, which actuates another switch 75, isdriven from some rotating shaft in the feeding unit, for example theshaft 7. The control circuit works in the following manner. When acorrection according to the above is cartied out in the feeding unit,the relay contact 63 receives a positive potential which, by a lead 76,is rled to the first part circuit in the control circuit. A relay havinga relay -coil 77 is activated rand holds over a relay contact 78 ann theswitch 75. At the same time a lamp 79 or the like in the indicator isilluminated and the condensator 69 is charged. Holding of the relay isbroken when the cam disc 74 activates the swtich 75 and, when the signalon the lead 76 has previously ceased, the lamp 79 is extinguished. Thecam disc 72 thereafter activates switch 71 whereby a circuit containingthe condenser 69 and the relay member 70 is closed which means that thecondenser is discharged through the coil of the relay and the relay isenergized. Holding of this relay occurs over another relay contact 80, arelay coil 81 and the current switch 75. At the same time a second lamp82 is illuminated and the condenser 73 charged. When the cam discs haverotated a further revolution, the sequence of events is repeated in thenext part circuit and due to this advance of the original signal on thelead 76, it is possible to see from the lamps how many revolutions theknife shaft 7 has rotated after the latest correction. When a newcorrection is made, a new advance begins from the first part circuit.

Due to the ability of the arrangement just described to easily controlthe 'adjustment of over feeding or under feeding of the strip, thetechnical effect of the invention has been appreciably improved. Withcertain of previously known feeding units, which lack this controlpossibility, the adjustment of the position of the strip has at thebeginning of a new strip and also during the sequence of operation,taken along time, and the rejection of wrongly cut sheets has beenlarge. However, if the control arrangement shall appear to fulladvantage, it is required that the feeding unit is provided with aneasily operated adjusting member for the rate of feed. In thearrangement according to the invention the fine adjustments are carriedout by this rate through the regulation of the number of revolutions `ofthe variator, which can easily be carried ou-t manually or by a .servomotor. It is clear from the above :description that the lgear 16, 17, 18and the input shaft 31 of the variator i-s driven from 'the same drivingsource. A completely similar lrelationship is hereby attained for thefeed and the correction independent of the speed of the arrangement. Inother, servo controlled feeding units, one often gets a completelydifferent function accuracy depending on the speed of the machine.

The invention has been described above in connection with the embodimentshown on the drawing but a number of modifications wi-thin the scope ofthe invention are possible. For example the cam disc switch 60 can bearranged so that the contact is broken up on actuation of the cam,whereby the disadvantage of contact rebound is eliminated. The discussedrelay functions must then be altered to their inverted functions. Itseems also possible to use `wholly electronic switches instead ofelectromagnetic relays.

What is claimed is:

1. A device for advancing a strip to be clipped into sheets of equalsize comprising a knife mounted on a rotatable shaft adapted to bedriven by la motor, driving means for advancing the strip relative tothe speed of said knife clipping the strip into sheets, whereby thesheet size and size accuracy is determined by the speed at which saiddriving means is operated, said driving means including at least onefeeding roll, a differential connected to the shaft of said feedingroll, first transmission means adapted to transfer a continu-ous drivingforce from said motor to said differential, second transmission meanscomprising a variator and a coupling, `which .are connected in series,electromagnetic control means for said coupling; said secondtransmission 4means connected in parallel with said first transmissionmeans between said motor and said differential whereby the driving speedto said feeding roll is composed of the driving speeds `.of said firstand second transmission means, the device also comprising a controlarrangement provided with la sensing arrangement sensitive to indicatingmeans on the strip and cam operated contacts and a switch controlled intime with the rotation of said knife; said control arrangement adapted,when signals of said sensin-g arrangement and said switch,respec-tively, lare coincident, to supply current to saidelectromagnetic control means for uncoupling said coupling upo-noperation of said cam operated contacts controlled by the rotation `ofsaid knife, and after a predetermined period determined by said camoperated contacts to recouple said coupling.

2. A device as claimed in claim 1, wherein said control arrangementincludes two electromagnetic relays of which one is excited when thesignals of said sensing arrangelment and said switch are coincident, andthe other relay is excited by |a coil having two holding cir-cuits ofwhich one circuit is opened by relay contacts provided lon said onerelay and the other circuit is opened by said cam operated contactscontrolled by the rotation of said knife; the latter of said two relaysbeing 4provided with a pair of lmake and break contacts for controllingcurrent to said electromagnetic control f-or uncoupling said couplingand engaging said coupling.

3. A device for advancing a strip to be clipped into sheets of equalsize comprising a knife mounted on a rot-atable shaft adapted to bedriven by a motor, driving means for advancing the strip relative to thespeed of said knife clipping the strip into sheets, said driving meansincoupling, which are connected in series with each other 5 and inlparallel with said first transmission means between said motor and saiddifferential, a control arnangefment provided with a sensing arrangementsensitive to indicating means on the strip and a switch controlled intime with the rotation of said knife; said control arrangement 10adapted, when signals of said sensing arrangement and said switch,respectively, are coincident, to uncouple said coupling for a period;the device also comprising a counting arrangement, for aiding incontrolling the setting of said Variiator to the correct feeding speedfor said strip, said counting .arrangement comprising a number ofindicators, a stepping means for moving successively a signal receivedin conjuction with 'an uncoupling of said coupling from one indicator toanother upon rotation of said knife to show the number of kniferotations between each uri-coupling operation.

References Cited by the Examiner UNITED STATES PATENTS 2,035,201 3/1936Smith etal 83-74 X 2,038,452 4/1936 Sharkey et al. 83-74 X 2,830,8114/1958 P-aul 83-74 X 2,995,968 8/1961 Tomberg 83-74 3,084,579 4/ 1963Melville 83-74 3,186,273 6/1965 Tomberg 83-74 15 WILLIAM W. DYER, IR.,Primary Examiner.

I. M. MEISTER, Assistant Examiner,

1. A DEVICE FOR ADVANCING A STRIP TO BE CLIPPED INTO SHEETS OF EQUALSIZE COMPRISING A KNIFE MOUNTED ON A ROTATABLE SHAFT ADAPTED TO BEDRIVEN BY A MOTOR, DRIVING MEANS FOR ADVANCING THE STRIP RELATIVE TO THESPEED OF SAID KNIFE CLIPPING THE STRIP INTO SHEETS, WHEREBY THE SHEETSIZE AND SIZE ACCURACY IS DETERMINED BY THE SPEED AT WHICH SAID DRIVINGMEANS IS OPERATED, SAID DRIVING MEANS INCLUDING AT LEAST ONE FEEDINGROLL, A DIFFERENTIAL CONNECTED TO THE SHAFT OF SAID FEEDING ROLL, FIRSTTRANSMISSION MEANS ADATPED TO TRANSFER A CONTINUOUS DRIVING FORCE FROMSAID MOTOR TO SAID DIFFERENTIAL, SECOND TRANSMISSION MEANS COMPRISING AVARIATOR AND A COUPLING, WHICH ARE CONNECTED IN SERIES, ELECTROMAGNETICCONTROL MEANS FOR SAID COUPLING; SAID SECOND TRANSMISSION MEANSCONNECTED IN PARALLEL WITH SAID FIRST TRANSMISSION MEANS BETWEEN SAIDMOTOR AND SAID DIFFERENTIAL WHEREBY THE DRIVING SPEED TO SAID FEEDINGROLL IS COMPOSED OF THE DRIVING SPEEDS OF SAID FIRST AND SECONDTRANSMISSION MEANS, THE DEVICE ALSO COMPRISING A CONTROL ARRANGEMENTPROVIDED WITH A SENSING ARRANGEMENT SENSITIVE TO INDICATING MEANS ON THESTRIP AND CAM OPERATED CONTACTS AND A SWITCH CONTROLLED IN TIME WITH THEROTATION OF SAID KNIFE; SAID CONTROL ARRANGEMENT ADAPTED, WHEN SIGNALSOF SAID SENSING ARRANGEMENT AND SAID SWITCH, RESPECTIVELY, ARECOINCIDENT, TO SUPPLY CURRENT TO SAID ELECTROMAGNETIC CONTROL MEANS FORUNCOUPLING SAID COUPLING UPON OPERATION OF SAID CAM OPERATED CONTACTSCONTROLLED BY THE ROTATION OF SAID KNIFE, AND AFTER A PREDETERMINEDPERIOD DETERMINED BY SAID CAM OPERATED CONTACTS TO RECOUPLE SAIDCOUPLING.